Those optical illusions are the result of beneficial adaptive strategies. Chronic illnesses are not beneficial. Let's keep that difference in mind.
But the illusions aren't a beneficial effect of beneficial adaptive strategies. They're a demonstration that brains do things that don't reflect cognition - that was the only point I was making there.
However, the idea that the brain can just malfunction independently is a hypothesis. [...] The brain... should not be the first option considered when hypothesizing about illnesses and should definitely not be the only option considered.
Harrison is talking about brain inflammation - I don't know that he's saying that it's independent of other processes in the body or that the brain is the only place we should look. I assume it's where he's looking because he's a brain guy.
So far we still have never cured any illness based on focusing on the brain as the source of the problem.
But there's a whole ton of diseases that we haven't cured. Maybe if we focused on the brain more, we'd cure a few. Or maybe not.
I'm happy that we've got people looking at the brain, mitochondria, the gut, the blood, the immune system, the muscles, the autonomic system, genomics, metabolomics, proteomics, all of it - we don't know what's wrong with us, and having a range of approaches seems like a good thing to do. I don't think we're too far off being able to synthesise our knowledge and narrow it down.